Research On Vehicle-track Coupling System Dynamic Characteristics And Reasonable Track Stiffness Of 32.5t Axle Load Heavy Haul Railway

Along with the rapid development of heavy haul railway, new type of heavy axle load of locomotive vehicles have come, but the study of 30 t axle load and above vehicle-track coupling dynamic responses and track stiffness have been rare.This paper is based on China Academy of Railway Science Railway science& Technology Research& Development Center foundation Track and bridge approach stiffness research to 30 t axle load and above on heavy haul(J2011G009). Research on dynamic characteristics of vehicle-track coupling system, rail structural component stiffness and overall stiffness have been done through combination of theoretical analysis, numerical simulation and experimental research. The main works and conclusions of this paper are as follows:(1)Quasi-static stiffness calculation for track. Track structural component stiffness for 32.5 t axle load on heavy haul has been calculated with allowable stress method and allowable deformation method. Recommended preliminary range of track structural component stiffness for 32.5 t axle load on heavy haul has been gotten.(2)Vehicle-track coupling dynamic characteristics and track structure component stiffness analysis. The coupling dynamic model of freight car with 32.5 t axle load and track system was constructed by the large wheel-rail dynamics software NUCARS. With the analysis method of dynamic sensitive coefficient, the dynamic characteristics of vehicles and track system under various stiffness combinations of track structure components were analysed to study the reasonable structural component stiffness for heavy haul railway under the action of freight car with 32.5 t axle load.(3)Track structure overall stiffness analysis.The new type of track system model was constructed by Midas to study the reasonable track structure overall stiffness based on the reasonable structural component stiffness for heavy haul railway; The dynamic model of freight car with 32.5 t axle load and track system was constructed by NUCARS. The dynamic characteristics of vehicles under different track structure overall stiffness were analysed to evaluate dynamic security and wheel-rail dynamic interaction characteristics.(4)Experimental study of Track structure overall stiffness with heavy haul railway. Constant load were applied by mobile load test car to test the track vertical stiffness of new 32.5 t axle load heavy haul railway. The test results have been compared with the results of the simulation analysis to verify its rationality.